All optical identification and sensor system with power on discovery

ABSTRACT

An apparatus and system having an optical integrated circuit (referred to herein as an OMTP) configured for power on during discovery and optically communicating with the OMTP reader for the purpose of extracting data.

This application claims the priority of U.S. Patent Application Ser. No.61/944,305, filed 25 Feb. 2014, the contents of which are incorporatedherein in their entirety.

Embodiments of the present invention generally relate to data collectionand communication systems and, more particularly, to an all opticalidentification and sensor system with power on discovery.

Radio frequency identification (RFID) devices are common devices fortracking, labeling, and identifying multiple specimens or objects. Thesedevices are often embedded in livestock or clothing and wirelesslycommunicate with an external reader using electromagnetic radio waves.However, opportunities for RFID tag miniaturization are often limited bya certain minimum antenna size requirements for achieving efficientoperation and useful range. Another limitation is the achievablelifetime of available local energy storage. Effective radiocommunication is reliant on having a certain minimum antenna size anddecreases in efficiency as antenna size is reduced such that below acertain physical size, radio communications become susceptible tofailure due to insufficient link budget. The size required of an antennais inversely proportional to frequency, thus directly proportional towavelength.

Most often RFID devices occupy a physical space that is too large forpractical tagging of smaller objects. In addition, research aboutbiological processes in a single cell is most often accomplishedindirectly by quantifying light using a variety of microscopictechniques.

Until now, direct measurements of certain characteristics of the milieuof a biological cell have been limited to methods using voltage clamptechniques, i.e., by placing a microelectrode inside the cell andsensing electrical parameters of the cell itself. However, thistechnique requires both electrical and mechanical contact with the cellat all times via conductive wires. In addition, because the techniqueused measures electrical parameters, there are constraints with regardto the type of measurements possible due to, for example, membranepotential which itself could bias the quantities being resolved as wellas the need to carefully control any applied voltages and/or currents toavoid causing effects on the cell that might artificially bias datacollection or even cause injury to the cell.

Therefore, there is a need in the art for an optical identification andsensor system with power on discovery that transmits data wirelessly toa data processor, able to be directly embedded within a cell.

SUMMARY OF THE INVENTION

Embodiments of the present invention comprise an optical identificationand sensor system that powers on with a first light beam andsubstantially simultaneously with discovery, transmits data via a secondlight beam (referred to herein as an all-optical micro-transponder or“OMTP”). In some embodiments, the OMTP may be configured forimplantation in a single cell and an OMTP reader for communicating withthe OMTP. The OMTP may gather data from within the cell and transmitsthe data to a remote reader. Further embodiments include tagging ofanimals (e.g., sub-dermal), test tubes, microscope slides, tissuesamples, and the like. While “tagging” shall mean includingidentification numbers such as for example inventory purposes, furtherembodiments with sensors (e.g., chemical, pH, temperature, and the like)allow for in-vivo real-time monitoring.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentinvention can be understood in detail, a more particular description ofthe invention, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

FIG. 1A depicts a block diagram of operation of the OMTP sensor systemin accordance with at least one embodiment of the invention;

FIG. 1B depicts a block diagram of the reader portion of the OMTP sensorsystem in accordance with at least one embodiment of the invention;

FIG. 2A depicts a block diagram of an optical detection circuit inaccordance with at least one embodiment of the invention;

FIGS. 2B and 2C depict encoding of the light for communication from theOMTP in accordance with at least one embodiment of the invention;

FIG. 3A depicts a cutaway view representation of an OMTP in accordancewith at least one embodiment of the invention;

FIGS. 3B and 3C depict an exemplary process flow assembly of themounting of LEDs on the OMTP substrate in accordance with at least oneembodiment of the invention;

FIG. 4 depicts a top plan view representation of an OMTP in accordancewith at least one embodiment of the invention;

FIG. 5 depicts a functional block diagram of an OMTP in accordance withat least one argument of the invention;

FIG. 6 depicts a flow diagram representing a method of operation of thecommunication system depicted in FIG. 1 in accordance with at least oneembodiment of the invention;

FIG. 7 shows a 3-layer OMTP;

FIG. 8 shows a controller/computer for use with the devices of theinvention.

DETAILED DESCRIPTION

FIG. 1A depicts a block diagram of operation of the OMTP sensor system180 in accordance with at least one embodiment of the invention. Thesystem 180 comprises an OMTP reader 102 and an OMTP 104. The OMTP 104 isdepicted as being adhered to a first sample microscope slide 185 ₁ ofmultiple sample slides 185 _(N). Each slide respectively has one OMTP104 with a unique identifiers such as an identification number or thelike. Thus, each slide (185 ₁ . . . 185 _(N)) may be uniquelyidentified. The slide 185 is an example, and may be any number of sizesrelative to the attached devices. Other example substrates include testanimals, or objects that require individual unique identification data.For example, in the scenario of supply chain management of clothing, theOMTP 104 may be larger for easier location by visual inspection than ona microscope slide 185 _(N) (where its location is in many embodimentspre-set). Further embodiments discussed herein include one of thesmallest examples of an OMTP 104, the implantation into a singlebiological cell.

As will be discussed further below, the OMTP 104 is an integratedcircuit that is normally in a persistent dormant unpowered state, and istypically powered on when illuminated with an excitation beam 132 fromthe OMTP reader 102. In embodiments, the OMTP 104 is not reliant onbattery energy storage, RF, or inductive power transfer to be powered.Upon illumination, the OMTP 104 instantly (e.g., much less than 1second) powers on and transmits a data beam 133 via light from the OMTP104. The data beam 133 in some embodiments may be an emission (e.g.,from a light emitting diode (LED)) or in other embodiments, areflection/absorption mechanism (e.g., shuttering via LCD). Inalternative embodiments, the OMTP 104 receives a separate stimulus suchas a code modulated onto the excitation beam 132 which initiatestransmission of the sensor data. Alternatively, receiving data from asensor triggers a transmission of the data beam 133.

In the depicted embodiment, excitation beam 132 is a visible laser beamand the data beam 133 is an infrared light beam emission (e.g., from aninfrared emitting diode). The data beam 133 for example contains asignal to identify the specific OMTP 104 to the OMTP reader 102 using anidentification number unique to the specific OMTP 104. Using theidentification number, the OMTP reader 102 may transmit data to acomputer to uniquely identify a given substrate. For example, a user mayselect a slide 185 ₁ containing a blood sample from a patient Y from acollection of slides 185 _(N) containing respective samples frompatients X, Y, and Z. The user then operates the OMTP reader 102 toilluminate the OMTP 104 on the slide 185 ₁ with a light (e.g., a redlaser beam) that causes the OMTP to transmit a data beam 133 via light(e.g., infrared). The data beam 133 is then received by the OMTP reader102. The OMTP reader 102 then decodes the data beam 133 carryingidentification data to unambiguously identify the slide 185 ₁ whichcarries a blood sample from patient Y as opposed to slides with bloodfrom patients X and Z.

FIG. 1B depicts a block diagram of the reader portion of the OMTP sensorsystem in accordance with at least one embodiment of the invention. FIG.1B includes an illustrative communication system 100 comprisingintegrated circuit (referred to hereinafter as OMTP 104) and an OMTPreader 102. The depicted embodiment in FIG. 1B is an example where theOMTP 104 is implanted into a biological cell 106. However, as discussedabove, the OMTP 104 may be adhered, embedded, and otherwise attached tovarious objects for instant or rapid transmission of identificationand/or accumulating and transmitting sensor data.

In some embodiments, the OMTP reader 102 may include an optical combiner125 that includes focusing lenses (126 and 127) for respectiveexcitation and data beams (132 and 133). In some embodiments, the OMTP104 has dimensions to facilitate implantation in a single cell 106. Assuch, the OMTP 104 is approximately 100 μm or less (e.g., 20 μm) on eachside. However, for larger cells, the OMTP 104 may be as large as 500 μmon each side. The OMTP 104 is enlarged in FIG. 1 to emphasize corecomponents of a substrate 160, photocells 150, and optical communicationcircuit 155. The height of the OMTP can be for example approximately 20μm-60 μm and dependent on the number of stacked layers and sensors for aparticular OMTP.

The OMTP reader 102 transmits the excitation beam 132 to activate theOMTP 104 and typically provide power to the OMTP 104. In response toreceiving the light 116, the OMTP 104 transmits data beam 133, such asfor example an infrared beam, that is received by the OMTP reader 102.The distance between the OMTP reader 102 and the OMTP 104 can be forexample on the order of 10 mm. The OMTP 104 can contain one or moresensors for gathering information about a cell. The OMTP 104 in such anembodiment can have an identification number that can be used touniquely identify or “tag” particular cells in a culture.

Laser shall be defined herein as coherent directional light which can bevisible light. A light source includes light from a light emitting diode(LED), solid state lasers, semiconductor lasers, and the like forcommunications. The excitation beam 132 in some embodiments may comprisevisible laser light (e.g., 660 nm wavelength). The excitation beam 132in operation may illuminate a larger area than that occupied by the OMTP104. The larger illumination area (not shown) allows the user to easilylocalize and read the OMTP 104. FIG. 1 emphasizes the excitation beam132 as illuminating the proper photocells 150, however other portions ofthe OMTP 104 may also be illuminated. In other embodiments, theexcitation beam 132 may comprise other wavelengths of light in thevisible and invisible spectrum necessary to supply sufficient powergeneration using photocells 150. For example, illumination with 60 mWaverage of focused optical power may generate a current of up to about 1mA and a power point voltage of up to about 1.2V in the photodiodes ofthe OMTP 104. As will be discussed further below, energy harvested fromthe excitation beam 132 and photocells 150 is used to actively transmitthe data beam 133 from the optical communication circuit 155. Additionalembodiments include photocells 150 to detect and extract asynchronization signal. The optical communication circuit 155 mayinclude a diode (not shown, e.g., infrared) and light modulationcircuitry (not shown) such that the data beam 133 (e.g., 1300 nm IRlight) is emitted with a different wavelength than the excitation beam132 (e.g., 660 nm red light).

However, other wavelengths, such as the near-infrared (NIR) band, may beused for optical communication. Alternative embodiments may usereflective signaling methods to return a modulated data signal to theOMTP reader via gated reflections of the emissions of the excitationbeam 132 from the reader 102. Gated Reflection methods may includeshuttering via liquid crystals, micro-electromechanical system (MEMS)structures, micro-mirrors, reflectance/fluorescence of a modulated dyesystem, and electro-chromic approaches.

The OMTP reader 102 may comprise a power supply 108, a controller 110, adriver 112 (such as a laser driver), a diode 114 (such as a laserdiode), a receiver/decoder 124, and an optical detection circuit. Insome embodiments, the OMPTO reader 102 further includes a first bandpass filter 120. The OMTP reader 102 in some embodiments is mounted to,or is made a part of, a stationary device (e.g., microscope, flowcytometer, and the like). In other embodiments, the OMTP reader 102 is ahandheld device (e.g., in a wand form factor) that is typicallyconnected to a standard personal computer or equivalent handheld device(not shown) via a wired or wireless interface. Both the mounted andhandheld embodiments include a computer interface for input/out 136.

In one embodiment, the controller 110 is may be based on amicrocontroller such as an 8051 microcontroller core by INTELcorporation in Santa Clara, Calif., which communicates with both theField Programmable Gate Array (FPGA) based receiver/decoder 124 and thedriver 112. In one embodiment, the driver 112 operates a diode 114 thatemits approximately 60 mW average of optical energy (when activelyreading) at a wavelength of 660 nm. In some embodiments, an opticalcollimation/focusing module (optic cube 115) may be positioned at theoutput of the diode 114 for the purpose of beam focusing, orredirection. In another option, an illumination system based on focusedhigh-intensity LED emissions may be employed. Optic cube 115 may referto beam prisms, amplification, redirection, and splitting devices. Opticcube refers generically to the interface between the reader's stimuluselectronics and the OMTP, and the readback interface between the OMTPand the IR transducer/resolver assembly.

Light generated as the excitation beam 132 is passed through the opticalcube 115 containing first optical bandpass filter 120 which may be a 660nm red bandpass optical filter. For example, the filter removes anyemissions from the response band, substantially at IR, assisting withdisambiguation of the stimulus beam from the response beam. Theexcitation beam 132 may continue through the optical combiner 125. Theoptical combiner 125 can comprise focusing lenses (126 and 127) tofurther provide isolation between the excitation beam 132 and the databeam 133. The optical combiner may encompass an aperture of a path ofthe data beam 133 to reduce stray light while collecting signal lightcomprising the data beam 133. As will be discussed further below,spectral coding can be applied using an optical filter (not shown)within the optical detection circuit 135.

In one embodiment, the light of the excitation beam 132 is amplitudemodulated at approximately 1 MHz. As shall be described with respect tothe FIGS. 2-6 below, the excitation beam 132 is typically used to powerthe OMTP 104. The modulation may be gated, applied in bursts, orotherwise provide pulse sequencing that is readily extracted by suitablydisposed photodiodes and extraction circuitry within the OMTP's logic.The timing of the laser emission pulse bursts are preferably set so thatthe emission durations and average laser power levels fall withinrequirements for registration as a class 3R laser device as defined inIEC standard 60825. Operation under class 3R does not require safetyglasses.

FIG. 2A depicts a functional block diagram of an illustrative opticaldetection circuit 135 in accordance with at least one embodiment of theinvention. The optical detection circuit 125 operates as a receiver thatcomprises photo detector 210, amplifier 215, data slicer 220, and ademodulator 225. In some embodiments, the optical detection circuit 125further includes a second band pass filter (BPF) 205. In operation, anIR (or NIR) signal (e.g., data beam 133) is received by the second bandpass filter 205. The second BPF 205 comprises a corresponding IR or NIRoptical BPF depending on the emitted light from the OMTP 104. Theenvironmental light and excitation light from the excitation beam 132incident on OMTP and host environment (e.g., cell 106) is therebyrejected.

The remaining data beam 133 is then detected by the photo detector 210.In some embodiments, the photo detector 210 is an IR photodiode, PINdiode, single junction detector, APD, or the like. The photo detector210 is coupled to amplifier 215. In some embodiments, the amplifier 215is a transimpedance amplifier to convert detected current from thephotodiode into a measurable voltage that can subsequently be readilyprocessed.

The output of amplifier 215 may be coupled to a data slicer 220. Thesignal is then sent to a demodulator 225 outputting extracted ID andsensor data for decoder 124. The extracted data includes but is notlimited to merely the identification of the OMTP, sensor data, and thelike. As will be discussed further below, alternative embodiments mayinclude sub-dermal applications to animals that may include sensors forimplantation and real-time detection of biological processes within ahost.

FIGS. 2B and 2C depict encoding of the light for communication from theOMTP in accordance with at least one embodiment of the invention.Encoding helps prevent interference occurring in the same opticalwavelength when undesirable scattered light (from the operatingenvironment or OMTP reading process) reaches photo detectors on thereceiver. FIG. 2B depicts the results of spectral coding in a graph 230of wavelength 232 versus light intensity 235. Spectral control isobtained using optical elements (e.g., optical BPF 205, optic cube 115,and the like) that are placed in the detector beam path. Spectralcontrol can be for example effected by having the stimulus and responsesignals occur at different wavelengths, simplifying separation from oneanother. From the graph 230, the incoming light 238 (e.g., excitationbeam 132) can be used for example for synchronization and energydelivery and is for example, of a shorter wavelength than the OMTPemitted light 242 (e.g., data beam 133). The optical filter cutoff 240can provide a high blocking ratio (e.g., order of 10⁵, 10⁶) of in-bandversus out-of-band light via long pass filters that yield the necessaryspectral separation thus facilitating disambiguation of the weak IR dataemissions from the OMTP from the strong excitation light and ambientlight.

FIG. 2C includes graphs (245, 250) that depict signal/noise advantagesfrom frequency encoding the signal of the excitation beam 132 fordistinguishing a synchronization signal data beam within the excitationbeam 132. First graph 245 is a plot showing the well-known 1/f noisecharacteristic along frequency axis 252. Band limited receiver inputsbenefit signal demodulation because in a band-limited channel, noise iscalculated as kTB. The noise power present in any bandwidth B is thusproportional to that bandwidth (and the operating temperature). Thus, ifthe signal is coded in a finite bandwidth B in the frequency domain, thesignal can be selected out using Band pass filters thus reducing out ofband noise, while further enhancing the signal to noise ratio throughthe use of synchronous demodulation techniques similar to lock-inamplifiers in the signal processor within the receiver. Such codingreduces the amount of noise 260 detected by the OMTP reader 102 in thepresence of the signal emitted by OMTP 104, thus avoidingself-interference. Essentially, the data rate of the returning signalfrom the OMTP 104 can be different from the stimulus modulationfrequency emitted by the OMTP reader permitting ready disambiguation ofthe response signals from the stimulus signals in the frequency domainvia synchronous demodulation, and secondly, the stimulus and responsewavelengths can be different permitting further disambiguation throughthe use of optical band-pass filters.

Graph 250 is a plot of the operating noise spectrum 255 across frequency265 versus noise power 262. Graph 250 uses coding separation to separatethe excitation beam 132 from the data beam 133. From the graph 250, bandlimited detection 258 is used to detect the incoming data signal fromOMTP. The detected synch signal is shown as the frequency response peak272 and the emitted signal for the data beam 133 is shown as frequencyresponse peak 268. Spectral line 272 is the stimulus modulation at 1 MHzand 268 is the data bearing IR return signal. Thus, from the graph 250,coding separation in some embodiments may further reduce communicationinterference in the system 100 and correspondingly enhance probabilityof intercept of the desired OMTP emission.

FIG. 3A depicts a side view representation of an illustrative OMTP 104in accordance with at least one embodiment of the invention. The OMTP104 comprises a stack of individual integrated circuit layers 300, 302,304, 306, 308. The layer 302 for example supports an emission/reflectionlayer and photocells; the layer 304 can comprise logic, clock, sensors,and transmitter circuits; layers 306 and 308 can comprise storagecapacitors; and layer 308 can also support the sensor electrodes 300.Those of skill in the art will recognize that functions of the OMTP canbe organized into layers of other configurations. As illustrated in FIG.1, the stacking may comprise layers of differing thicknesses uniformlyoverlaid so as to be manufacturable in a 3D IC process well-known in theart.

The OMTP 104 can be manufactured for example using mixed-signalmanufacturing technology that is typically used to makethree-dimensional (3D) integrated, 55 nm, dynamic random access memory(DRAM) and 65 nm mixed-signal process devices. In an illustrativeembodiment, each layer is approximately 12 μm thick and 100 μm×100 μm indimension. In one embodiment, dimensions of the OMTP 104 are 100×100×50μm. Alternative embodiments may use more or less layers.

FIGS. 3B and 3C depict an exemplary process flow assembly 710 of themounting of LEDs on the OMTP substrate in accordance with at least oneembodiment of the invention. The process flow 710 is an exemplarymonolithic process of bonding and patterning LEDs for emitting the databeam 133 using a loophole technique. In some embodiments, the LEDs maybe organic LEDs (OLEDs) or other light emission device, e.g. a blackbody emitter. In this embodiment, in providing step 705, a compoundsemiconductor wafer 312 comprising a GaAs substrate 316, an AlAs releaselayer 318, LED layers 320 (with p- and n-junctions) and a siliconsubstrate 314 are bonded.

The exemplary process flow 710 begins at step 720 where the InGaAs andSi wafers (312 and 314) are bonded using an insulating adhesive (e.g.,polyimide resin). Next, at step 722, vents are cut into the wafer 312and thinned using back grinding. Then at step 725, the wafer 312 isreleased using high frequency etching to expose the p- and n-junctionson the backside. At step 727, LED mesas are patterned to singulate theLEDs. Then at step 728 an insulating layer is deposited and patterned toreveal contact bond pads. Lastly at step 730, the non-insulated voids inthe pattern are metallized to form connections to the LEDs. Alignment iscrucial for the formation and accurate bonding of the OMTP. In someembodiments, backside reference marks or IR through-wafer alignments maybe used for the process flow 710.

FIG. 3C shows a detailed cross sectional view of steps 727, 727, 730,focusing on the end indicated by the circles in FIG. 3B. Step 730provides an exemplary LED 332 on the OMTP 104 that emits at for examplethe IR or NIR band. The p- and n-regions (338 p, 338 n) are etched andexposed for topside contact and isolated by insulation 340. An adhesive335 for example bonds the LED 338 to the Si substrate 314. P- andN-contacts (334, 336) are for example coupled to the Si substrate 314using VIAs (342, 344). Such VIAs (342, 344) in some embodiments may bethrough-silicon VIAs (TSVs). The Si substrate 314 may be realized usinga silicon-on-insulator (SOI) architecture so as to take advantage of theopportunity to develop higher operating voltages for use with shorterwavelength emitters, e.g. in visible wavelengths. In some embodiments,the OMTP 104 is bonded or adhered via adhesive to an object so as tooperate as an identifier for the object.

FIG. 4 is a top plan view representation of an illustrative OMTP 104 inaccordance with at least one embodiment of the invention. The view is ofthe top layer 302 of FIG. 3A. In one embodiment, the top layer 302comprises an LED array 400 that circumscribes the periphery of the OMTP104. In other embodiments, an LED array may be realized as a single LEDor other topography for directed light emission. The placement of theLED array 400 depicts an example of an embodiment emphasizing lightgeneration. Alternative embodiments may include varying topographylayouts favoring power harvesting or capturing sensor data and the like.In some embodiments, the LEDs may include focusing lenses or otheroptics.

Centrally located on the top layer 302 is for example an array 401 ofphotocells 402, 404, 406, and 408. As illustrated, each photocell inarray 401 is physically sized to create power for a particular circuitwithin the OMTP 104 and one is dedicated to clock/carrier signalextraction. Photocell 402, the largest in area, produces V_(dd) for theelectronic radiation transmitter (realized as a LED in the opticalcommunication circuit 155). Photocell 406 produces an exemplary voltage,V_(ss) for output transistor 416. Photocell 408 is used to extract clockpulses for logical state machine sequencing and photocell 404 producesanother exemplary voltage, V_(dd) for the logic and sensor circuits. Asillustrated, the power cells are coupled to capacitors for example, inlayers 306 or 308 for storing the energy produced by the photocells whenilluminated by laser light; in embodiments, the clock photocell (408) isnot low pass filtered as the power harvest elements are in order topermit extraction of clock pulse edges due to the stimulus lightmodulation. In some embodiments, energy extracted from the clockphotocell (408) is applied to a differentiator (not shown) whichextracts clock edges which are amplified and used to provide timingsignals to the logical and sensing circuits. As illustrated, a pluralityof identification fuses 418 is located on the surface 414. By openingselect ones of these fuses, the OMTP is provided a unique identificationcode range beyond a default base page of code values that are hard-codedinto the chip logic. In an alternative embodiment, the ID values may beelectronically coded using electronic antifuse technology. Further stillare embodiments with electronic memory for data, signal processing, andidentification storage.

Exemplary logic area 410 can for example be covered in goldmetallization. Angle chevrons 412 can for example be used as alignmenttargets during serialization of the wafer on a site-wise basis.

FIG. 5 depicts a functional block diagram of an illustrative OMTP 104 inaccordance with at least one embodiment of the invention. The OMTP 104comprises a set of photocells 150 (402, 404, 406, 408), energy storage504, clock/carrier extraction network 506, sensors 508, logic 501,transmit switching circuit 512, and an LED 155 (e.g., IR).

The photocells 150 can include dedicated photocells such as a clockextraction photocell 408, energy harvesting photocell array 404, 406,and transmit photocell 402. As described above, the energy harvestingphotocell array 404 and 406 may be coupled to energy storage 504 and maycomprise photovoltaic cells. Photovoltaic cells convert light energyfrom illumination into an electron current.

One embodiment of a photocell-based integrated circuit power supply canbe for example as described in commonly assigned U.S. Pat. No.7,098,394, which is hereby incorporated herein by reference in itsentirety. The clock photocell 408 detects a synchronization signal forthe clock/carrier extraction circuit 506. In one embodiment, the energystorage 504 is a plurality of capacitors having at least one capacitorcoupled to a photocell of the photocell array 404, 406. The energystored in the energy storage unit 504 is coupled to the electroniccircuits. Since the laser light is pulsed, the energy from the laser isaccumulated and the OMTP 104 will operate on the stored energy. Duringthe operation period, the transmitter switching circuit 512 via outputtransistor 416 can “dump” all of its energy into the IR LED 155. As thereceived laser pulse energy is extracted by the clock/carrier extractioncircuit 506, the logical state machine forms data packets comprising theID bits and sensor data and provides these to the transmit data switchfor the formation of the transmission IR signal. The logic 510 maydirectly integrate the sensor and ID signal(s) into the composite dataframe of the OOK (on-off keyed) light emitter. The modulation symbolsare applied to the transmitter 512 and transmitted with each pulse ofenergy.

The sensor(s) 508 can comprise one or more sensors for measuring cellcharacteristics. In one embodiment, sensors 508 will have an assay timeand power dissipation confined by the power source, such as an assaytime of less than 10 ms and power dissipation of less than 4 μW at 1.2V. The analog data from the sensor may be converted into a pulse widthmodulated signal or other binary signaling method that encodes theanalog quantity in the time domain in a manner suitable for pulsing theIR emitting diode for direct transmission to the OMTP reader 102 withoutthe need for traditional, power and area intensive analog to digitalconversion techniques. Exemplary sensors include a dielectric sensor, aproportional to absolute temperature (PTAT) sensor, a pH sensor, a redoxpotential sensor, and/or light sensor. Various available sensors thatcan be integrated into the OMTP are described below.

A dielectric sensor monitors the dielectric constant of acustom-designed capacitor on the OMTP surface. External material, suchas DNA or proteins, can be attached to the chip surface by an electricfield or surface chemical coating. See for example, WO2011/137325entitled “Metal Nanoparticle Structures for Enhancing Fluorescence-BasedAssays” incorporated herein by reference in its entirety. As theexternal material influences the effective dielectric constant of theinsulating material between two plates of the capacitance sensingcircuit, the net capacitance changes. This influence can change withbinding of materials to for example surface nucleic acid, protein, orother material. This change can be measured, in one embodiment, byhaving the quantity to be measured form the capacitive element in an RCtime constant circuit where the capacitor is made of the sensor platesand the attached material itself. Ideally, the resultant RC productcould be tuned to provide a nominal time constant in the 0.121 ms range,varying in accordance with the change in capacitance commensurate withthe quantity being measured. The resulting variance in the timing, inturn, is used to control the duty cycle of an internally derived pulsesignal that is used to modulate the emissions from the OMTP 104. Themodulated emissions convey the sensor's data to the reader. Availableclock references derived from the laser pulses are used as timingsources. This technique yields a potential sensor precision in the rangeof 14 bits as expressed in the digital domain. Dielectric sensors aresensitive to pH and ionic strength changes for similar reasons, and assuch, broadly applicable. Unit-to-unit calibration may be needed, thusknowing the OMTP identification number can be additionally important.The calibration information (i.e., slope and intercept) for a particularOMTP sensor may be stored in a database and accessed based on the OMTPidentification number.

In some embodiments, the OMTP 104 may be a sub-dermal implantationwithin a human or host animal in which the excitation beam 132 and databeam 133 operates at a sufficient power for the required skinpenetration depth. The OMTP 104 may be passivated with SiO₂ to providesurface protection and insulation against the environment whileproviding a nonreactive surface. Openings in the passivation can beprovided to allow for analysis of biological particles. In suchembodiments, snapshot readings from biosensors may allow instantdetection and monitoring of blood glucose, cholesterol, fats,temperature, blood alcohol content, and the like. For example, animplanted OMTP may include biosensors to provide blood diagnostics fordiabetics, chemotherapy patients, radiation therapy patients,alcoholics, and the like. For example, an OMTP 104 with a temperaturemeasuring sensor may exploit the temperature dependence of the voltageacross a forward biased PN junction such as in a PTAT sensor.Temperature sensing elements in PTAT sensors comprise two differentdiode connected bipolar transistors. The two diodes are biased by twocurrents whose ratio is constant with temperature, so that thedifference between the voltages across the two diodes is proportional toabsolute temperature. A differencing amplifier extracts this voltage andthis voltage is converted to a duty cycle with an integrating digitizeror other simple, low power analog to digital converter (ADC) elementrealized on-chip.

Alternatively, changes in resistance of an element on the OMTP 104 dueto temperature change may be used to measure temperature with highsensitivity with operation as a thermistor.

In some embodiments, a pH sensor based on an ion sensitive field effecttransistor (ISFET) can be arranged, where a small change in the inputvoltage due to pH variation, results in a larger change in current atthe output. This is classic FET behavior, where the transconductance(dI_(o)/dV_(i)) is the figure of merit. This property is well understoodand very repeatable. The voltage dependence on pH is linear over a widerange. Another sensor topology suitable to integration is anintracellular oxidation (redox) potential sensor, a marker of exposureto ionizing radiation, including potential DNA damage and aging. Anothersensor that may be used is a light sensor for imaging the inside of thecell, using existing photocell technology. Commonly realizable Siliconphotodiodes have useful spectral response across the entire visiblelight band.

Each sensor produces an output that may be directly modulated onto thecarrier frequency yielded by the clock extraction circuit 506 usingappropriate modulation methods.

FIG. 6 depicts an illustrative flow diagram of a method 600 of operationof the communication system 100 in FIG. 1 in accordance with at leastone embodiment of the invention. The method 600 as a first portion 601depicting the operation of the OMTP reader and a second portion 602depicting the operation of the OMTP.

A method 600 begins with the reader portion 601 at step 604 and proceedsto step 606. At step 606, the laser is modulated at, for example, 1 MHzand, at step 608, light is applied from the laser to the OMTP. At step610, the OMTP receives the light from the laser and, at step 612, storesthe power generated by the laser light illuminating the photocells. Inone embodiment, steps 604 through 612 are performed in approximately 1μS

At step 614, for example, the stored power is applied to the sensor(s),the clock, the logic, and a transmitter. At step 616, the method 600outputs the sensor data as an IR signal using duty cycle modulation forthe sensor data and NRZ data coding for the ID portion of thetransmission. At step 618, the transmitter causes emission of the databy driving current into the IR diode over the period of a clock cycle.As represented by box 626, steps 616 and 618 can be performedsimultaneously.

At step 620, the method 600 receives the signal transmitted from theOMTP and is filtered for step 622. At step 622, the OMTP receiverdemodulates the received signal to extract the sensor and ID data. Atstep 624, the method 600 processes and stores the data typically using acomputer that is connected to the OMTP reader. In this manner, in vivocell information is collected and communicated to the reader forprocessing. Useful memory sizes include for example from 32 bits to asmany as 256 or even more. 64 bits is sufficient for a large number ofapplications. On one wafer site, 10 mm×10 mm in size for example, 108OMTPs can be made. The structure of one wafer may include 1,000 suchsites, thus the total number of chips made from one wafer can approach1011. Anticipating that thousands if not millions of such wafers aremade, unique IDs are desirable. 64 bits provides up to 2×1019 differentIDs. However, if the desire is to have more complex ID encoding toreduce the ID readout error rate, or a CRC (cyclic redundancy check) onthe OMTP in addition to the ID, and if the number of wafers produced iseven larger than stated above, then a 96 bit or 128 bit memory can beused for such a production series.

Complete encoding of the memory could include the sitewise ID and itsCRC encoded during production of the CMOS wafer, as well the site number(within the wafer) and the wafer number. The latter two can be forexample encoded electrically by virtue of having proper wiring withinthe streets of the wafer. In embodiments, on-chip memory can be maderewritable (e.g., RERAM), then the site and wafer IDs can be opticallyencoded at the site level, for example by illuminating the site withproperly encoded modulated light.

Exemplary Small Embodiment

For many applications, such as in biology, chemistry or tagging, thesmaller the OMTP the greater the utility. Smaller OMTPs are desirablefrom the perspective of multiplexing in chemical synthesis andbioassays, for their lower unit cost and in secure applications theimplicitly covert nature of such a small size is particularlyadvantageous. The dimensions of the OMTP described herein can be forexample on the order of 15×15×15 μm (micrometer, i.e., micron).

The micron sized all-optical OMTP can be built for example from threewafer fragments:

TABLE 1. A light energy receiving element that is a photocell made fromcompound semiconductor; 2. Logic including the memory, clock-decodingand signal generating circuits; this circuit is made using a CMOSprocess on silicon wafers; 3. A light-emitting element, such as an LED,also made from compound semiconductor.

An illustrative such OMTP 800 is shown in FIG. 7, formed with layer 802(e.g., photocell layer), layer 804 (e.g., logic and memory layer) andlayer 806 (e.g. LED layer). Layer 802 is, for example, made from acompound semiconductor such as GaAs. The wafer is thinned to 2 micronsfor example. The sizing of the OMTP provides a higher voltage andgreater efficiency. The illustrative design provides the ability tostack the photodiode over the logic, which reduces the OMTP linear area.One light-receiving element can provide electrical power for allcircuits on the chip.

In this and the other embodiments, a logic wafer can be plated with alayer of for example gold on one or both sides of the thinned wafer toprotect the logic functions from the potentially disruptive effects ofthe illuminating light. Plating can spread across most of the primarysurface, or selectively as needed for protection. In this and the otherembodiments, a logic layer can include a power distribution controlcircuit that supplies sufficient power to both the logic elements andthe LED elements.

In this and the other embodiments, the feature size of a suitable CMOSprocess can be for example 28 nm or less, such as 11 nm. The typicalsize of the CMOS wafer is 8″ to 12″. The wafer is thinned to 10 micron.Segments of the wafer are used for assembly as appropriate.

In this and the other embodiments, a great variety of LEDs exist and areapplicable. They are capable of emitting light ranging from below 400 nmto 2000 nm and the chemical composition of the wafer can varycorrespondingly. For example, the LED could be made from InP and emit IRat around 1300 nm. The LED wafer can be thinned for example to 2 micron.

In principle, light is emitted by the LED in all directions (e.g., IRlight). However, in the exemplary configuration depicted in FIG. 7,since the gold coating of the middle IC layer will reflect light, thenet result is that the light is emitted by the LED into the half-sphere,mostly in the opposite direction from the interrogating beam of light.If another direction is desired, other configuration can be used. Forexample, the LED can be placed as a middle of three layers, the lightemitted by the LED directly and the light reflected by the protective(e.g., gold) coating on the integrated circuit containing the logic andmemory will pass through (at least partially) the photocell layer,mostly towards the illuminating light source. In other embodiments, theprotective plating on a logic layer can more selective or missing, suchthat LED light emissions pass through.

Illustrative layers 802 and 804 are connected for example by a singlevia 812 and two pads (822), as shown in FIG. 7. The diameter of a via isfor example around 1 micron. Illustrative layers 804 and 806 areconnected for example by a pair of vias (814, 816), and two pads (824),as shown in FIG. 7.

The ordering of the three layers can be different than that shown inFIG. 7. The photocell and LED layers are very thin and transparent tolight or translucent, allowing for alternate configurations.

After the wafer-scale alignment of the wafers or wafer fragments, athree-wafer sandwich is formed. OMTPs are singulated through chemical orionic dicing of the wafer sandwich, or an alternative method.

In embodiments, the OMTP (whether 3 layer or not) is about 80 micron orless in its longest dimension (length, width, height). In embodiments,it is about 60 micron or less, or about 50 micron or less, or about 40micron or less, or about 30 micron or less, or about 20 micron or less,or about 15 micron in its longest dimension. In embodiments, the OMTP isconstructed from three wafer fragments. Where the OMTP includes asensor, in embodiments such an OMTP is constructed from four waferfragments.

Additional Uses

The OMTPs can be used in combinatorial synthesis to generate a largenumber of compounds. Oligonucleotides (DNA and RNA), peptides and smallchemical molecules can be synthesized in a precisely controlled manner.It is possible to sort the OMTPs in accordance with their IDs during thesynthesis; this allows defined chemical compounds to be made onpredetermined OMTPs. See, for example, U.S. Prov. Appn. 62/093,819,filed 18 Dec. 2014 (Genomic-Scaled Nucleic Acid Synthesis . . . ), thecontents of which are incorporated herein in their entirety.

The OMTPs can be used in multiplex solid phase bioassays, e.g., ELISA.They can provide an attractive alternative or a replacement for theLuminex fluorescent bead in many assays. They can be used in DNA assaysas well. See, for example, U.S. application Ser. No. 14/053,938, filed15 Oct. 2013 (Compact Analyzer . . . ); and U.S. Pat. No. 8,785,352(Metal Nanoparticle Structures for Enhancing Fluoresence Based Assays).The entire content of the aforementioned patent documents isincorporated herein in its entirety.

The OMTPs can be used for tagging variety of objects and animals. Astags on objects, they can be used to secure these same objects againstcounterfeit by identifying the provenance of the object unambiguously.The OMTPs can be placed on objects in predetermined locations, or mixedinto a coating material, such as paint or ink. They can be sprinkledinto paper during production.

For tagging or monitoring animals, they can be injected into the animal.In embodiments, the OMTPs are placed near the surface of the skin. See,for example, U.S. Pat. No. 8,353,917 (Apparatus and Method to Deliver aMicrochip), the contents of which are incorporated herein in theirentirety.

In embodiments, the OMTPs are embedded into the paper, plastic, cloth,other material, or composites thereof in a high security document, suchas paper money, securities, id documents, passports, or the like. Forexample, the OMTPs can be impressed into the fibers of paper or cloth,such that they will not be displaced during use, or they can be placedduring production. For plastics, they can for example be placed bylamination.

In embodiments, such OMTPS are about 80 micron or less in largestdimension. In embodiments, such documents are scanned for printedsubject matter (serial number, 1D or 2D bar code, or the like) and forthe digital ids for the one or more OMTPs placed therein. An automatedvalidation program retrieves the expected correspondence from aconfidential database. In embodiments, the query sent to the databaseserver(s) by a database authorized device is the information taken fromthe printed subject matter. The reply for example includes in encryptedform the OMTP ids. An authorized device can be configured to make thevalidating comparison without providing the id numbers to any user,merely providing a validation or rejection message or signal.

The device can incorporate the written subject matter reader, the OMTPreader (light query and emitted light reader), and validation programing(with the database typically remotely located). In embodiments, thedevice reads OMTPs that are correctly located on the document.

Various elements, devices, modules and circuits are described above inassociation with their respective functions. These elements, devices,modules and circuits are in embodiments considered means for performingtheir respective functions as described herein.

Controller/Computer

In any aspect that calls for a controller or computer, the devices ofthe invention can have a controller 750 (FIG. 8), which can comprise acentral processing unit (CPU) 754, a memory 752, and support circuits756 for the CPU 754 and is coupled to and controls the analyzer or,alternatively, operates to do so in conjunction with computers (orcontrollers) connected to the analyzer. For example, another electronicdevice can supply software, or operations may be calculated off-sitewith controller 750 coordinating off-sight computer operations with thelocal environment. The controller 750 may be one of any form ofgeneral-purpose computer processor, or an array of processors, that canbe used for controlling various devices and sub-processors. The memory,or computer-readable medium, 752 of the CPU 754 may be one or more ofreadily available memory such as random access memory (RAM), read onlymemory (ROM), flash memory, floppy disk, hard disk, or any other form ofdigital storage, local or remote. The support circuits 56 are coupled tothe CPU 54 for supporting the processor in a conventional manner. Thesecircuits can include cache, power supplies, clock circuits, input/outputcircuitry and subsystems, and the like. Methods of operating theanalyzer may be stored in the memory 752 as software routine that may beexecuted or invoked to control the operation of the devices. Thesoftware routine may also be stored and/or executed by a second CPU (notshown) that is remotely located from the hardware being controlled bythe CPU 754. While the discussion in this patent application may speakof the “controller” taking certain actions, it will be recognized thatit may take such action in conjunction with connected devices.

All ranges recited herein include ranges therebetween, and can beinclusive or exclusive of the endpoints. Optional included ranges arefrom integer values therebetween (or inclusive of one originalendpoint), at the order of magnitude recited or the next smaller orderof magnitude. For example, if the lower range value is 0.2, optionalincluded endpoints can be 0.3, 0.4, . . . 1.1, 1.2, and the like, aswell as 1, 2, 3 and the like; if the higher range is 8, optionalincluded endpoints can be 7, 6, and the like, as well as 7.9, 7.8, andthe like. One-sided boundaries, such as 3 or more, similarly includeconsistent boundaries (or ranges) starting at integer values at therecited order of magnitude or one lower. For example, 3 or more includes4 or more, or 3.1 or more.

FURTHER EMBODIMENTS, NUMBERED EMBODIMENTS

Any embodiment described herein that can logically be combined withanother described herein, such that a person of ordinary skill wouldrecognize that they can desirably be combined, are contemplated towithin the invention. For example, any sizing for the integrated circuitdescribed above is contemplated for all embodiments. The invention canbe described further with reference to the following numberedembodiments:

Embodiment 1

An optical integrated circuit comprising: (A) an optical transmitterconfigured for sending data to an external optical receiving device; and(B) at least one photovoltaic power source powered by receiving lightfrom a light source.

Embodiment 2

The integrated circuit of embodiment 1, further comprising memory and alogic circuit.

Embodiment 3

The integrated circuit of embodiment 2, wherein the logic circuit andmemory is coupled to the optical transmitter for transmitting datacomprising identification data unique to the integrated circuit.

Embodiment 4

The integrated circuit of one of the foregoing embodiments, furthercomprising at least one sensor measuring environmental data fortransmission by the optical transmitter.

Embodiment 5

The integrated circuit of embodiment 4, wherein environmental dataincludes at least one of: temperature, dielectric conditions, protein,or blood glucose levels.

Embodiment 6

The integrated circuit of one of the foregoing embodiments, furthercomprising topology configured for at least two of: implanting into abiological cell, embedding into a sub-dermal skin, or adhesion to anobject.

Embodiment 7

The integrated circuit of one of the foregoing embodiments, wherein theintegrated circuit concurrently receives a synchronization signal andpower from the light source as light operating at a first wavelength.

Embodiment 8

The integrated circuit of embodiment 7, wherein the optical transmittersends a data signal with light at a second wavelength.

Embodiment 9

The integrated circuit of one of the foregoing embodiments, wherein theoptical transmitter operates in the infrared spectrum and the opticalreceiver operates in the visible spectrum.

Embodiment 10

The integrated circuit of one of the foregoing embodiments, wherein uponpowering by the at least one photovoltaic power source, the integratedcircuit is configured to optically transmit identification data to anoptical reader.

Embodiment 11

The integrated circuit of one of the foregoing embodiments, furthercomprising receiving at least one of clock data and coding data forsubsequently controlling the optical transmitter to send data.

Embodiment 12

An optical communication system for communicating with an opticalintegrated circuit, the system comprising: (I) an optical integratedcircuit comprising at least one photovoltaic power source and an opticaltransmitter; and (II) an optical reader comprising a laser light sourcepowering the photovoltaic power source and a photosensor receiving lightfrom the optical transmitter.

Embodiment 13

The system of embodiment 12, wherein the laser light source is modulatedfor simultaneously providing energy and timing signals to the opticalintegrated circuit.

Embodiment 14

The system of one of the foregoing embodiments 12 or 13, wherein theoptical reader further comprises a decoder for decoding the receivedlight from the optical transmitter into data.

Embodiment 15

The system of embodiment 14, wherein the data includes identificationdata unique to each optical integrated circuit.

Embodiment 16

The system of one of the foregoing embodiments 12-15, wherein theintegrated circuit further comprises at least one sensor, the at leastone sensor measuring the environment surrounding the optical integratedcircuit.

Embodiment 17

The system of one of the foregoing embodiments 12-16, further comprisingwherein the data receiver photosensor operates in the infrared lightspectrum and the laser light stimulation source operates in the visiblespectrum.

Embodiment 18

A method for communicating between an optical integrated circuit and anoptical reader comprising: (A) illuminating the optical integratedcircuit with directed light from a modulated laser source in the opticalreader; (B) powering at least one photovoltaic cell of the opticalintegrated circuit (IC); and (C) transmitting a data signal with anoptical transmitter of the optical integrated circuit that is powered bythe at least one photovoltaic cell.

Embodiment 19

The method of embodiment 18, wherein, the transmitted data signal isreceived by a photosensor of the optical reader for decoding.

Embodiment 20

The method of one of the foregoing embodiments 18-19, wherein the datasignal includes unique identification data of the optical integratedcircuit and wherein the optical transmitter sends a data signal usinglight at a second longer wavelength.

Embodiment 21

The method circuit of one of the foregoing embodiments 18-20, whereinthe optical receiver on the optical IC concurrently receives asynchronization signal at the optical receiver and power from the lightsource as light operating at a first wavelength.

Embodiment 22

The method of one of the foregoing embodiments 18-21, wherein the datasignal further comprises data from a sensor coupled to the opticalintegrated circuit.

While the foregoing is directed to embodiments of the present invention,other and further embodiments of the invention may be devised withoutdeparting from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

Publications and references, including but not limited to patents andpatent applications, cited in this specification are herein incorporatedby reference in their entirety in the entire portion cited as if eachindividual publication or reference were specifically and individuallyindicated to be incorporated by reference herein as being fully setforth. Any patent application to which this application claims priorityis also incorporated by reference herein in the manner described abovefor publications and references.

1. An optical integrated circuit comprising: an optical transmitterconfigured for sending a data signal to an external optical receivingdevice; and one or more photovoltaic power sources powered by receivinglight from a light source, said one or more photovoltaic power sourcesnecessary and sufficient to power the optical transmitter; one or morelogic circuits and memory coupled to the optical transmitter fortransmitting data comprising identification data for the integratedcircuit; wherein the integrated circuit is configured to concurrentlyreceive from the light source (a) a synchronization signal and (b) powerfrom the light source; and wherein the integrated circuit comprises aclock extraction function configured to extract a clock from thesynchronization signal to establish a data rate frequency fortransmitting the data.
 2. The integrated circuit of claim 1, whereineach of the length, width and height of the optical integrated circuitis about 500 micrometers or less.
 3. The integrated circuit of claim 1,wherein the optical transmitter for transmitting data comprises an LED.4. The integrated circuit of claim 1, further comprising at least onesensor measuring environmental data for transmission by the opticaltransmitter.
 5. (canceled)
 6. The integrated circuit of claim 1, whereinthe integrated circuit concurrently receives a synchronization signaland power from the light source as light operating at a firstwavelength, and the optical transmitter sends a data signal with lightat a second wavelength.
 7. The integrated circuit of claim 6, whereinthe second wavelength is longer than the first.
 8. The integratedcircuit of claim 1, wherein the optical transmitter operates in theinfrared spectrum and the optical receiver operates in the visiblespectrum.
 9. The integrated circuit of claim 1, wherein the opticaltransmitter is formed of one or more pieces of silicon, and at least onephotovoltaic power source is formed of one or more separate pieces ofsilicon.
 10. (canceled)
 11. An optical communication system forcommunicating with an optical integrated circuit, the system comprising:the optical integrated circuit according to claim 1; and an opticalreader comprising a laser light source powering the photovoltaic powersource and sending the synchronization signal and a photosensor forreceiving light from the optical transmitter, the optical readerconfigured to extract the identification data.
 12. The system of claim11, wherein the laser light source is modulated for simultaneouslyproviding energy and synchronization signals to the optical integratedcircuit.
 13. (canceled)
 14. The system of claim 11, wherein theintegrated circuit further comprises at least one sensor, the at leastone sensor measuring the environment surrounding the optical integratedcircuit, wherein environmental data from the sensor is encoded in lightfrom the optical transmitter, and wherein the optical reader isconfigured to decode the environmental data.
 15. The system of claim 11,wherein the optical transmitter operates in the infrared spectrum andthe optical receiver operates in the visible spectrum.
 16. A method forcommunicating between an optical integrated circuit according to claim 1and an optical reader comprising: illuminating the optical integratedcircuit with directed light from a modulated laser source in the opticalreader; powering at least one photovoltaic cell of the opticalintegrated circuit; and transmitting the data signal with an opticaltransmitter of the optical integrated circuit that is powered by the atleast one photovoltaic cell.
 17. (canceled)
 18. The method of claim 16,wherein the optical transmitter sends the data signal using light at asecond longer wavelength.
 19. (canceled)
 20. The method of claim 16,wherein the data signal further comprises data from a sensor coupled tothe optical integrated circuit.
 21. An optical integrated circuitcomprising: an optical transmitter configured for sending data to anexternal optical receiving device; and one or more photovoltaic powersources powered by receiving light from a light source, said one or morephotovoltaic power sources necessary and sufficient to power the opticaltransmitter; one or more logic circuits and memory coupled to theoptical transmitter for transmitting data comprising identification datafor the integrated circuit; and wherein the optical transmitter isformed of one or more pieces of silicon, and at least one photovoltaicpower source is formed of one or more separate pieces of silicon. 22.The integrated circuit of claim 22, wherein the integrated circuit isconfigured to concurrently receive from the light source (a) asynchronization signal and (b) power from the light source; and whereinthe integrated circuit comprises a clock extraction function configuredto extract a clock from the synchronization signal to establish a datarate frequency for transmitting the data.
 23. The integrated circuit ofclaim 22, wherein the integrated circuit does not have an RF antennae.24. The integrated circuit of claim 1, wherein each of the length, widthand height of the optical integrated circuit is about 500 micrometers orless.
 25. A method of operating an integrated circuit of claim 4,comprising embedding the integrated circuit in a biological cell andremotely obtaining therefrom environmental data from the sensor.